code: def forward(self, cosine: torch.Tensor, label):
      index = torch.where(label != -1)[0]
      m_hot = torch.zeros(
          index.size()[0], cosine.size()[1], device=cosine.device
      )
      m_hot.scatter_(1, label[index, None], self.m)
      cosine.acos_()
      cosine[index] += m_hot
      cosine.cos_().mul_(self.s)
      return cosine
  
file_path: insightface/recognition/vpl/losses.py
imports: import torch
  from torch import nn
label_desc: Use image node_id 2 for calling the ArcFace obj's underlying member method code with example usage: obj.forward(cosine, label) and returns: cosine